Not Applicable
Robotic devices are known which transport various articles of manufacture around a manufacturing facility. In semiconductor wafer manufacturing operations, robotic devices are used to transport carriers such as cassettes containing semiconductor wafers through various stages of the wafer manufacturing process. These cassettes, or pods, are frequently lifted and moved by such robotic devices. One type of pod includes a handle or crown extending from the upper surface of the pod that can be grasped by an overhead robot arm. This crown includes a plate attached to a stem. The plate extends beyond or overhangs the sides of the stem to form a flange that can be grasped by the robot arm.
Wafer manufacturing operations typically require a contaminant-free environment, or clean room. Particulate contaminants which can be generated by mechanical abrasion and lubricants are avoided in a clean room environment. Accordingly, robotic devices for use in a clean room minimize moving and motorized parts which can contribute to particulate contamination.
Further, wafer pods concentrate a substantial quantity of wafer product in a common payload element. Bumping, jarring, and dropping of a wafer pod, such as through a power failure or operator error, can result in substantial payload losses. Also, efficiency of space suggests that clean room robotics should avoid positional dependencies, such as requiring side access to a pod.
Accordingly, it would be beneficial to provide a robotic device which has minimal moving parts, which can maintain a pod payload throughout power failures and operator error, and which allows for top access to a pod to avoid imposing location constraints on adjacent robotic equipment.
A wafer pod handling device engages a pod for transport through a flange on top of the pod by receiving the flange into a receptacle and rotating a circular disk having a square aperture such that edges on the disk are positioned beneath an overhang on the flange. As the circular disk is lifted, the edges contact the overhang of the flange and lift the pod. The circular disk is mounted in a housing having a lip adapted to slideably engage the circumference of the circular disk. An actuator on top of the housing rotates the disk into engagement with the flange. As the housing is lifted, the circumference of the circular disk rests on the lip to frictionally secure and support the circular disk despite power failures or accidental rotation which could disengage the pod.